Armature mounting structure in an electromagnetically operated switch

ABSTRACT

A structure for mounting and guiding the movements of an armature in an electromagnetically operated switch. The structure for mounting the armature includes a pair of members which are secured on opposite ends of the armature to connect the armature to the free ends on the arms of a U-shaped movable contact carrier. The movable contact carrier has a bight portion movable in a slot in a rear wall of a molded base that carries the stationary contacts of the switch on its front face. The bight portion is guided during its movement in the slot by a bearing portion which is centrally located on the bight portion and received in a central portion of the slot. The free ends on the arms of the carrier and the armature are guided during their movements by portions of a frame which positions a stationary magnet part and a magnet coil and four posts which extend from a molded member that acts as an arc suppressing barrier for the switch.

United States Patent Puetz et al.

[54] ARMATURE MOUNTING STRUCTURE IN AN ELECTROMAGNETICALLY OPERATED SWITCH [72] Inventors: Jordan F. Puetz, Milwaukee; James E.

Stallman, Whitefish Bay, both of Wis.

[73] Assignee: Square D Company, Park Ridge, Ill.

[22] Filed: Dec. 18, 1970 [211 Appl. No.: 99,574

[ Feb. 15, 1972 Primary Examiner-Harold Broome Attorneyl-larold J. Rathbun and William H. Schmeling [57] ABSTRACT A structure for mounting and guiding the movements of an armature in an electromagnetically operated switch. The structure for mounting the armature includes a pair of members which are secured on opposite ends of the armature to connect the armature to the free ends on the arms of a U-shaped movable contact carrier. The movable contact carrier has a bight portion movablein a slot in a rear wall of a molded base that carries the stationary contacts of the switch on its front face. The bight portion is guided during its movement in the slot by a bearing portion which is centrally located on the bight portion and received in a central portion of the slot. The free ends on the arms of the carrier and the armature are guided during their movements by portions of a frame which positions a stationary magnet part and a magnet coil and four posts which extend from a molded member that acts as an arc suppressing barrier for the switch.

10 Claims, 5 Drawing Figures PATENIEDFEB 15 I972 SHEET 1 BF 3 l N VEN] 0R. JORDAN F PUETZ JAMES E. STALLMAN ARMATURE MOUNTING STRUCTURE IN AN ELECTROMAGNETIC/ALLY OPERATED SWITCI-I The present invention relates to electromagnetically operated switching devices, and more particularly to a structure for mounting an armature and for guiding the movements of the armature and a movable contact carrier in an electromagnetically operated switch.

Electromagnetic switching devices, of the type with which the present invention is concerned, are commonly known as contactors and are furnished as switching units of various sizes, having ratings which are normally in accordance with the standards promulgated by the National Electrical Manufacturers Asociation, commonly known as NEMA, Among the commercial requirements which a contactor is required to satisfy are that the contactor must be constructed so it can be easily mounted and wired on a panel and that the partsof the contactor be arranged so it is easy to inspect and replace the various components, such as the switching contacts and coil of the contactor while the contactor is wired on the panel.

In larger sized contactors, i.e., NEMA Size 5 contactors which are rated to carry 300 amperes or less, a magnet of considerable size and weight is required to exert the force required to cause a proper engagement betweenthe movable and the stationary contacts of the contactor. Thus from a design standpoint, the relatively heavy magnet in the contactor should be located as close as possible to the panel. However, present commercial requirements dictate that the most desirable form of a contactor should have its line or supply wire connections at the top of the device and the load wire connections at the bottom-of the device to provide an arrangement which is commonly termed as straight-thru wiring. Further, the commercial requirements dictate that the wire connecting terminals be freely accessible and located as close to the panel as electrical clearance requirements will permit. Thus, if a contactor is to have a simple economical construction, a minimum size for its rated capacity and isto include a straight-thru wiring feature, the design requirements dictate that it is impractical to mount the magnet portion of the contact directly on the panel. Therefore, in the device according to the present invention, the magnet is carried forwardly of the base which supports the stationary contacts and wire connecting terminals so that the readily device may bereadily wired on the panel with straight-thru wiring and may be readily disassembled to permit the movable and the stationary contacts to be serviced. Further in the contactor according to the present invention, the magnet armature is arranged to move toward the base when the electromagnet is energized to provide an economical simplified contactor structure. As the contactor construction herein described is intended for the larger size NEMA rated devices, it necessarily includes relatively heavy armature'which generates a considerable impact shock when the electromagnet is energized. The undesirable effects of the impact shock are minimized by a structure which includes a shock plate which supports the electromagnet and is mounted on four sturdy posts that extend from the molded base of the contactor. The four posts have inserts molded therein which extend to the mounting panel so that the shock accompanying the engagement between the armature and stationary magnet part is directly transmitted to thejmounting panel and in effect bypasses the base. Further, a molded barrier which encloses the contacts so as to isolate the poles of the contactor from each other and ground is suspended from the shock plate so as to be out of engagement with the base. Thus the shock is not transmitted through the barrier to the base and the inspection and servicing of the contact structure is readily accomplished by merely removing the screws securing the shock plate to the posts so that the entire assembly, including the electromagnet and barrier, may be removed to make the contacts of the structure readily accessible. The structure for mounting the electromagnet on the shock plate includes a pair of members which are secured to each other and to fingers that extend from the forward surface of the shock plate. The pair of members provide a rectangular frame that surrounds the stationary magnet and provide an arrangement whereby the coil may be readily removed for replacement purposes. The members further provide a guide for the armature and a structure for resiliently supporting the stationary magnet so the magnet has a limited movement on the shock plate to reduce the noise when pole faces of the armature and magnet are in engagement with each other and the shock which accompanies the impact between the armature and the stationary magnet when the electromagnet is initially energized.

The contactor structure further includes a molded insulating barrier which cooperates with the base to provide spaced compartments wherein the switching contacts of the contactor operate and a cover, which is secured to portions of the barrier by four screws and resiliently positions the coil onthe members providing the rectangular frame that positions the stationary magnet. A pair of members which are secured to the opposite ends of the annature in turn are secured to the free ends on the arms of the movable contact carrier by a pair of screws. Thus easy access to the coil is obtained by merely loosening the four screws which secure the cover and the two screws which mount the armature on the arms of the movable contact carrier. The portions of the barrier to which the cover is secured also provide surfaces which guide the movement of the members which connect the armature to the movable contact carrier. The movable contact carrier, which is U-shaped and has its bight portion movable in a slot in the rear wall of the base, has a bearing on its bight portion which is guided by portions of the slot. Thus the armature and movable contact carrier are guided at three spaced locations in a plane to assure proper movement of the armature and the movable contact carrier in the plane.

It is an object of the present invention to provide an electromagnetically operated switch that is easy to wire and service and includes an arrangement for connecting an armature to a movable contact carrier of the switch which will guide the movement of the armature and carrier and is easy to disassemble so a coil of the switch may be readily replaced.

An additional object is to provide an electromagnetically operated switchv with an inexpensive readily detachable connection between an armature and a movable contact carrier of the switch andto use the connection to guide the movements of the armature and the carrier in a plane.

A further object is to provide an electromagnetically operated switch with an inexpensive readily detachable connection between an armature and a movable contact carrier of the switch and to provide guide surfaces on a mounting for a stationary magnet and a coil positioning structure as well as guide surfaces on a barrier which isolates the movable contacts and stationary contacts of the switch which will engage the connection and thereby guide the movement of the armature and the carrier.

Another object is to provide an electromagnetically operated switch with an inexpensive readily detachable connection between an armature and a movable contact carrier of the switch and to provide guide surfaces on a mounting for a stationary magnetand a coil positioning structure as well as guide surfaces on a barrier which isolates the movable contacts and stationary contacts of the switch which will engage the connection and thereby guide the movement of the armature and the carrier and to provide a bight portion of the carrier with a bearing which is received in a slot in a rear wall of the base that has the stationary contacts mounted on its front surface so that the contact carrier is guided at three spaced locations in a plane.

Further objects and features of the invention will be readily apparent to those skilled in the art from the specification and drawings illustrating a certain preferred embodiment in which:

FIG. 1 is a partly exploded view showing in perspective certain components of an electromagnetically operated switching device that incorporates the features according to the present invention.

FIG. 2 is a top end view of the assembled device in FIG. I with portions broken away to illustrate a connection between an armature and a movable contact carrier in the device.

FIG. 3 is a cross-sectional view taken along line'3-3 in FIG.

2. FIG. 4 is a side view of the device in FIG. 2.

FIG. 5 is a view of a movable contact carrier and an armature as used in the device in FIG. 1 with portions thereof broken away to illustrate a connection between the armature and the movable contact carrier that incorporates the features of the present invention.

For the convenience in description, the electromagnet switch or contactor is described herein as disposed in a horizontal position when the contactor is mounted on a front wall of a vertical panel, the parts of the contactor being described in relation to this position. Accordingly, the terms front and rear, upper and lower, vertical and horizontal and the like are not absolute but merely define more readily the relative positions of portions of the parts and their relative positions to each other when the contactor is mounted on a panel.

Referring to the drawings, an electromagnetic switch assembly is shown as having a plurality of components that are stacked one upon the other. The components of the assembly 10 include a metal mounting plate 12, an insulating base 14, an insulating barrier 16, a shock plate 18, an electromagnetic assembly 20, a cover 22 and a movable contact carrier 24. v

As disclosed in an application for U.S. Pat. having a Ser. No. 99,613, concurrently filed herewith, the contactor structure is arranged so that the'shock plate 18 rests on four posts which extend forwardly of the base 14. The shock plate 18 mounts the barrier 16 in spaced relation to the base 14 to provide easy access to the movable and stationary contact structures of the device and transmits the magnet closing shock directly through the four posts to the mounting plate 12. Similarly, the details of the cover 22 and the functions which the cover 22 provides are disclosed in an application for U.S. Pat, Ser. No. 99,573, which is concurrently filed herewith.

As shown in FIGS. 1 and 2, the metal mounting plate is formed as a stamped metal part to provide a means to secure the switch assembly 10 to a vertical panel and the like, not shown. When the plate 12 is secured to the panel, an edge 26 becomes the bottom edge of the plate 12 and a surface 28 the front surface of the plate 12. The plate 12 has a pair of rearwardly extending indentations 30 along its bottom edge 26 that provide a pair of spaced mounting feet having openings therein. The plate 12 also has an indentation 32 at its top edge which provides an elongated mounting foot having an opening therein which, together with the indentations 30, are provided for the purpose of securing the plate 12 to a vertical panel.

The switch 10, as shown in FIG. 1, is a three pole device in that it is capable of completing and interrupting a three phase circuit when the switch 10 is actuated and deactuated. To enable the switch 10 to function as a three pole device, the base 14 and the barrier 16 are formed of a molded insulated material having arc suppressing capabilities and cooperate with each other to provide three compartments which extend parallel between a top and a bottom of the switch 10. Positioned in each compartment is a set of stationary contact assemblies 34 and a movable contact 36 in a manner disclosed in an application for U.S. Pat., Ser. No. 99,612, concurrently filed herewith. Extending into the material of the base forwardly of a rear surface 38 and through the sidewalls 40 of the base 14 is a slot 42. The slot 42 is centered on a centerline equidistant between a top wall 44 and a bottom wall 46 of the base 14 and is exposedto each of the compartments on a front side 48 of the base 14 by a passage 50. Positioned on the front side 48 on opposite sides of the centerline of the base 14 in each of the compartments is the pair of stationary contact assemblies 34 which are respectively connected to a terminal member 52. The terminal members 52 are arranged to accept the bared end of a wire conductor and are electrically connected to the stationary contacts within the compartment. The movable contact carrier 24 is generally U-shaped, having a bight 54 or body portion received in the slot 42 and a pair of arm portions 56 extending externally of the sidewalls 40 of the base 14 and the sidewalls 58 of the barrier 16. The arm portions 56 are connected to an armature 60 of the electromagnetic assembly 20 and are moved rearwardly toward the plate 12 when the electromagnet assembly 20 is energized. At least one pair of compressinn'springs 62 positioned between a rear wall 64 of the bight portion 54 and the plate 12 cause the movable contact carrier 24 to be positioned forwardly when the electromagnetic assembly 20 is deenergized. Extending from the bight portion 54 of the contact carrier 24 into each of the compartments is a projection 66 which provides a mounting surface 68 for one of the movable contact assemblies 36. Each of the movable contact assemblies 36 includes a spring-biased releasable retainer 70 and a movablecontact 36'which engages the stationary contacts 34 in a manner fully disclosed in the application for U.S. Pat., Ser. No. 99.612, supra.

Extending forwardly from the front side 48 of the base 14 are four spaced posts 72, each of which has a front surface 74 that is spaced from the remaining portions of the front side 48 of the base 14. The posts 72, which are more clearly described in the application for U.S. Pat., Ser. No. 99,613, supra, have metal inserts embedded therein that have a rear end flush with the rear surface 38 of the base 14 and extend substantially throughout the molded material of theposts 72. The inserts have threaded bores at their opposite ends which are respectively used to mount the base 14 on the metal mounting plate 12 and receive screws 76 at their forward end which mount the shock plate 18 on the front surfaces 74.

The shock plate 18 is formed as a metal plate having. a thickness so it will resist deformation wh en it is mounted on the surfaces 74 provided by the four spaced posts 72. The posts 72 extend from the front surface of the base 12 so two of the posts 72 are on each side of a plane that is normal to the rear surface 38 and passes through the horizontal center of the base 14. The shock plate 18 has a front surface 78 and a rear surface 80 and four openings located therein to be aligned with the threaded bores in the four posts 72 when the rear surface 80 is positioned on the front surfaces 74. The shock plate 18 is mounted on the front surfaces 74 in spaced relation to the front side 48 of the base 14 by the four screws 76 which pass through the openings in the shock plate 18 and are threaded into the inserts in the posts72. The shock plate 18 has an additional four spaced openings which receive four screws 82 to mount the barrier 16 on the rear surface 80. The barrier 16 has suitable inserts molded therein to receive the screws 82 so as to be suspended on the shock plate 18 with all the portions of its rear surface in spaced relation to the surface portions on the front side 48 of the base 14.

The shock plate 18 has a rectangularly shaped centrally located depression extending in its front surface 76 which provides a mounting surface 84 that extends between the walls of the barrier 16. Extending downwardly and forwardly on the lower side of the mounting surface 84 are a pair of spaced fingers 86 each of which has a support surface 88 spaced forwardly of the front surface 78 and has a threaded opening therein. Similarly extending upwardly and forwardly from the upper side of the mounting surface 84 are a pair of spaced fingers 90, also having a support surface 92 with threaded openings therein. The support surfaces 88 and 92 are all equally spaced forwardly of the front surface 78. A pad 94 of suitable elastomeric material, such as Buna N rubber, is secured to the mounting surface 84 to have its front surface substantially flush with the front surface 78.

In addition to the armature 60, the electromagnet assembly 20 includes a stationary magnet part 96 and a magnet coil 98. The stationary magnet 96 is E-shaped and formed of a stack of E-shaped laminated magnet iron pieces which are positioned between a pair of E-shaped nonmagnetic iron plates which are secured together by strategically located rivets to provide a unitary assembly in a manner well known to those skilled in the art. The magnet 96 is shaped to provide poles at its opposite ends having forwardly facing pole faces 106 and 108 thereon and a centerpole that is located centrally between the pole faces 106 and 108 which provides a centerpole face 110. The end walls 104 of the magnet 96 are each shaped to provide a projection, not shown, that presents forwardly facing support surfaces at the opposite end walls 104 of the magnet 96 whereon pads, not shown, and formed of a suitable elastomeric material, such as Buna N rubber, are positioned.

A means for mounting the stationary magnet 96 on the elastomeric pad 94, positioning the magnet coil 98 on the stationary magnet 96 and guiding the armature 60 during its movements, includes a pair of members 112 and 114 which are fully disclosed in the application for US. Pat., Ser. No. 99,614, supra. The members 112 and 114 areidentical and are each formed as an L-shaped metal part to have leg portions which are arranged to provide a rectangular frame when the members 112 and 114 are secured to each other and to the support surfaces 88 and 92 by screws 116 which are threaded into the threaded openings in the support surfaces 88 and 92.

The frame provided by the members 112 and 114 is spaced forwardly of the shock plate and surrounds the magnet 96. The leg portions on the members 112 and 114 have a pair of projections thereon which engage the sidewalls and portions of the end walls 104 of the magnet 96 to position the magnet 96 against movement in a direction parallel tothe mounting surface 84. When the members 112 and 114 are mounted on the fingers 86 and 90, a rear surface on the leg portions of the members 112 and 114 will be positioned against the forward facing surface on the elastomeric pads on the end walls 104 so the magnet 96 will be resiliently mounted against movement in a direction vertical to the mounting plate 12 by the elastomeric pad 94 and the elastomeric pads on the end walls 104. The legs of the members 112 and 114 each have openings, not shown, therein and respectively have portions 118 and 120 that extend forwardly from the remaining portions of the members 112 and 114.

The magnet coil 98 is formed as an encapsulated molded bodywhich has a coil winding embedded therein connected to input, terminals 122 which are externally accessible on a front side 124 of the coil 98. The molded body forming the coil 98 has a rear side 126 and a rectangularly shaped passage 128 extending between the rear side 126 and the front side 124. The passage 128 is sized to receive the portion of the magnet 96 that provides the central pole face 110. Additionally, the coil 98 has four mounting pads 130 located at the corners of a rectangle extending from its rear side 126. The pads 130 have projections 132 extending therefrom. The projections 132 have tapered ends and are located at the rear side 126 to be received in the openings in themembers 112 and 114 to position the coil 98 against movement in a plane parallel to the mounting plate 12 while the pads 130 engaging the front surface of the members 112 and 114 position the coil against rearward movement in the switch 10. Thus the members 112 and 114 position the coil 98 against movement in any of three directions. The coil 98 is formed so as to surround the centerpole face 110 and be received in the spaces between the centerpole face 110 and the pole faces 106 and 108.

The armature 60 includes a stack of laminated magnet iron pieces 134 which are positioned between a pair of nonmagnetic metal parts 136. The laminated pieces 134 and the parts 136 are secured together by strategically located rivets 138 and the pieces 134 are shaped to provide pole faces 140 and 142 which are aligned to engage the respective pole faces 106 and 108 and a centerpole face 144 which is aligned with the centerpole face 110 on the stationary magnet 96. Each of the metal parts 136 has an L-shaped cross section and is formed of relatively thick metal to have leg portions 146 and 148. The 1 side that presents an arcuately shaped surface 164 and a portion 166 that is received between the portions of the legs 146 and 148 that form the portions 150. The members 156 and 158 are each secured to the portions 150 by a pair of screws 168 which extend through suitable bores in the members 156 and 158 and are received in threaded openings that are located in portions of the legs 148 that fom1 the portions 150. When the members 156 and 158 are secured to the parts 134. the arcuate surfaces 164 will be spaced from the ends 152 and 154. The elastomeric members 160 and 162 are received between notched portions 172 in the leg portions 148 and have a portion 174 positioned on the front side of the pieces 134 and a portion 176 that is trapped between portions of the end walls 152 and 154 of the pieces 134, the surface 164 and the portions 150. The members 160 and 162 each have a front surface 177 that is spaced forwardly of the front sides of the legs 148.

The barrier 16 has four posts 178 extending forwardly of the surface which is secured to the shock plate 18. The four posts 178 are located to provide a pair of spaced posts that extend forwardly from the left side and a pair of spaced posts that extend forwardly from the right side of the barrier 16. Each of the posts 178 has a surface 180 facing a horizontal plane extending through the center line of the slot 42 with the surfaces 180 on the respective posts being arranged to extend parallel and be equidistantly spaced from the horizontal plane that extends through the centerline of the slot 42. Each of the posts has a U-shaped metal part 182 positioned thereon and a threaded insert, not shown, embedded therein that is aligned with an opening 184 in a bight portion 185 of the U-shaped metal part 182 when a leg portion 186 of the U-shaped part is positioned adjacent the surface 180. The leg portions 186 on the respective posts 178 provide guide surfaces that face the horizontal plane that extends through the centerline of the slots 42. The members 156 and 158 have surfaces 188 at their respective upper and lower ends juxtaposed to the surfaces provided by the legs 186 to guide the armature 60 and the arm portions 56 of the movable contact carrier 24 against vertical displacement in a horizontal plane during the movement of the armature 60 and the contact carrier 24. The members 156 and 158 each have a bore therein which is aligned with a threaded insert that is exposed to an opening 192 in the free ends of the arm portions 56 to receive a screw 194 which secures the members 156 and 158 to the armature 60 to the arms 56 of the movable contact carrier 24.

A portion of the base 12 providing the central portion of the slot 42 is arranged to provide a pair of facing grooves which receive a bearing member 196. The bearing member 196 is centrally positioned on the bight portion 54 and is received in the grooves to guide the bight portion 54 of the movable contact carrier 24 during its movements in the slot 42. The hearing member 196 is formed as a U-shaped molded part of a flexible molded material having wear-resistant characteristics and embraces the central portion of the bight portion 54 as shown in FIGS. 3 and 5.

The portions 118 and 120 on the members 112 and 114 each have a curved surface 198 engaging the arcuate surfaces 164 on the respective members 156 and 158 to prevent a horizontal displacement of the armature 60 and the free ends 190 of the movable contact carrier 24 in the horizontal plane passing through the centerline of the slot 42. Thus the guiding engagement between the curved surface 198 and the arcuate surfaces 164 and the guiding engagement between the surfaces 188 and the legs 186 will guide the movement of the armature 60 and the movable contact carrier 24 at two spaced locations while the bearing member 196 provides a guide for the movement of the movable contact carrier 24 at a third location in the horizontal plane passing through the centerline of the slot 42.

The cover 22 is formed from a relatively thick metal piece to have a U-shaped channellike shape which provides a bight portion 200, a pair of legs 202 and 204, extending from the bight. portion, and flanges 206 and 208 which extend outwardly from the legs 202 and 204 which form the U-shaped channel. The flanges 206 and 208 each have openings at their opposite ends which receive screws 210 that are aligned to be passed through the openings 184 and be threaded into the inserts within the posts 178 to secure the cover to the front surfaces of the posts 178. Each of the flanges 206 and 208 has an opening therein which receives a stem portion of a plunger 212 that is biased by a spring 214. The plunger 212 extending from the flange 206 is shown in FIG. 3 and the plunger 212 extending from the flange 208 is shown in FIG. 2. The plungers 212 each have a headed portion 216 on one end and a groove which receives a C-shaped fastener 218 at its opposite end. The fasteners 218 are positioned to engage the front surfaces of the flanges 206 and 208 to maintain the plungers 212 captive in the openings in the flanges 206 and 208' when the springs 214 which surround the stem portions of the plungers 212 are positioned between the headed portions 216 and the rear surfaces of the flanges 206 and 208. The plungers 212 are located in the flanges 206 and 208 so the headed portions 216 respectively engage the portions of the front side 124 on diagonally opposite sides of the passage 128. When the screws 210 are tightened in the inserts in the posts 178, the stem portions on the plungers 212 will move in the openings in the flanges 206 and 208 and cause the pads 130 to be maintained in their position on the members 112 and 114 so that the coil 98 is resiliently held against movement in a forward direction on the stationary magnet96. The cover 22 may be removed from the switch 10 by loosening and removing the four screws 210. When the cover 22 is removed, easy access to the coil 98 is obtained and all that is required to replace the coil 98 is to detach the armature 60 from the movable contact carrier 24 by removing screws 194 and lift the coil 98 from its position on the magnet 96 and insert a new coil in the position occupied by the replaced coil before the armature 60 and the cover 22 are replaced. 1

The switch 10 also includes a suitable arc suppressing means that includes a plurality of arc plates 220 which are secured to the barrier 16 and operate in a manner well known to those skilled in the art. Access to the stationary and movable contacts of the switch 10 is readily obtained by removing the four screws 76 and the pair of screws 194 that secure the members 156 and 158 to the ends of the arms 56 so that the assembly, including the shock plate 18, the barrier 16, the electromagnet assembly 20, as well as the cover 22, is removed as a unit from the base 14 while the movable contact carrier 24 remains assembled with the base 14. The removal of the shock plate 18 and the components attached thereto will expose the stationary contacts assemblies 34 as well as the movable contacts'36 for inspection. The replacement of the stationary contacts is readily accomplished by removing the screws holding the supports for the stationary contact surfaces and substituting new supports and replacing the screws. The replacement of the movable contacts is readily accomplished in a manner described in the application for US. Pat., Ser. No. 99,612, supra.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an electromagnetically operated switch, the combination comprising: an insulating base having a front side, a rear wall and sidewalls extending between the front side and the rear wall, a plurality of pairs of stationary contacts mounted on the front side with the contacts of each pair spaced equidistantly from a plane that extends normal to the rear wall, an insulating barrier having sidewalls, a front wall, and a plurality of spaced partitions extending between the sidewalls on the barrier rearwardly from the front wall cooperating with the front side of the base to define a plurality of compartments with each of said compartments having a pair of the stationary contacts therein, a U-shaped insulating movable contact carrier having a bight portion and arm portions centered in the plane, said arm portions extending forwardly from opposite ends of the bight portion externally of the sidewalls of the barrier to provide mounting surfaces on the free ends of the arms that are spaced forwardly of the front wall of the barrier, and a plurality of spaced projections extending from the bight portion to provide a movable contact support surface in each of said compartments that is spaced forwardly of the front side of the base, a movable contact positioned on each contact support surface to engage the pair of stationary contacts within the compartment, an electromagnet assembly including: a magnet coil, a stationary magnet part having a pair of spaced pole faces facing in a common direction and an armature having a pair of opposite ends and pole faces at the opposite ends that face in a common direction and are spaced to engage the pole faces on the stationary magnet part, means including a frame for mounting the stationary magnet part and the magnet coil forwardly of the front wall of the barrier so the pole faces on the stationary magnet are centered in the plane and face in a forward direction and for positioning the magnet coil on the stationary magnet so a magnet flux is induced in the stationary magnet part when the magnet coil is energized, means including a pair of members for mounting the opposite ends of the armature on the mounting surfaces provided by the arms of the carrier so the pole faces on the armature face in a rearward direction and engage the pole faces on the stationary magnet part when the magnet coil is energized and the armature moves from a dcenergized position in a rearward direction in said plane to an energized position, means including a spring for moving the carrier and the armature from the energized position to the dcenergized position when themagnet coil is deenergized, and means for guiding the movement of the armature and the carrier during movement between said energized and dcenergized position,said guiding means including two pairs of portions on the barrier extending forwardly of the front wall of the barrier to provide a pair of spaced parallel walls at each of the two sides of the front wall of the barrier with the walls of each pair of the parallel walls confronting each other and extending parallel to the plane to engage opposite ends of one of the pair of members for guiding the movement of the armature along an axis in said plane and a pair of portions on the frame each respectively engaging a sidewall portion on one of the pair of molded members for preventing movement of the armature along an axis in the plane that is parallel to the rear surface of the base during the movement of the armature and carrier between the energized and dcenergized positions.

2. The combination as recited in claim 1 wherein the base includes a slot centered in the planes extends in the rear wall and through the sidewalls and a plurality of spaced passages centered in the plane and extend between a front side of the slot and the front side of the base and the bight portion of the carrier is movable in the slot, the arm portions extend externally ofthe sidewalls of the base and the projections extend forwardly from the bight portion and through the passages.

3. The combination as recited in claim 2 wherein the plane is centered between a pair of end walls of the base.

4. The combination as recited in claim 3 wherein each of said members is formed of a molded material and has an arcuate surface which is engaged by one of said portions on the frame.

5. The combination as recited in claim 4 wherein the armature includes a stack of laminated magnet metal parts which provide the opposite ends and pole faces and a pair of nonmagnetic metal members each having a length greater than the length of the magnet metal parts and wherein the nonmagnetic members are secured to opposite sides of the stack to provide portions extending from each of the opposite ends of the stack to which the molded members are secured.

6. The combination as recited in claim 2 wherein the movable contact carrier hasa bearing surface located centrally on its bight portion and the slot has a portion which cooperates with the bearing surface to guide the movement of the bight portion during the movement of the armature.

7. The combination as recited in claim 6 wherein the plane is centered between a pair of end walls of the base.

8. The combination as recited in claim 7 wherein each of said members is formed of a molded material and has an arcuate surface which is engaged by one of said portions on the frame.

9. The combination as recited in claim 8 wherein the armature includes a stack of laminated magnet metal parts which provide the opposite ends and pole faces and a pair of nonmagnetic metal members each having a length greater than the length of the magnet metal parts and wherein the nonmag- 

1. In an electromagnetically operated switch, the combination comprising: an insulating base having a front side, a rear wall and sidewalls extending between the front side and the rear wall, a plurality of pairs of stationary contacts mounted on the front side with the contacts of each pair spaced equidistantly from a plane that extends normal to the rear wall, an insulating barrier having sidewalls, a front wall, and a plurality of spaced partitions extending between the sidewalls on the barrier rearwardly from the front wall cooperating with the front side of the base to define a plurality of compartments with each of said compartments having a pair of the stationary contacts therein, a U-shaped insulating movable contact carrier having a bight portion and arm portions centered in the plane, said arm portions extending forwardly from opposite ends of the bight portion externally of the sidewalls of the barrier to provide mounting surfaces on the free ends of the arms that are spaced forwardly of the front wall of the barrier, and a plurality of spaced projections extending from the bight portion to provide a movable contact support surface in each of said compartments that is spaced forwardly of the front side of the base, a movable contact positioned on each contact support surface to engage the pair of stationary contacts within the compartment, an electromagnet assembly inCluding: a magnet coil, a stationary magnet part having a pair of spaced pole faces facing in a common direction and an armature having a pair of opposite ends and pole faces at the opposite ends that face in a common direction and are spaced to engage the pole faces on the stationary magnet part, means including a frame for mounting the stationary magnet part and the magnet coil forwardly of the front wall of the barrier so the pole faces on the stationary magnet are centered in the plane and face in a forward direction and for positioning the magnet coil on the stationary magnet so a magnet flux is induced in the stationary magnet part when the magnet coil is energized, means including a pair of members for mounting the opposite ends of the armature on the mounting surfaces provided by the arms of the carrier so the pole faces on the armature face in a rearward direction and engage the pole faces on the stationary magnet part when the magnet coil is energized and the armature moves from a deenergized position in a rearward direction in said plane to an energized position, means including a spring for moving the carrier and the armature from the energized position to the deenergized position when the magnet coil is deenergized, and means for guiding the movement of the armature and the carrier during movement between said energized and deenergized position, said guiding means including two pairs of portions on the barrier extending forwardly of the front wall of the barrier to provide a pair of spaced parallel walls at each of the two sides of the front wall of the barrier with the walls of each pair of the parallel walls confronting each other and extending parallel to the plane to engage opposite ends of one of the pair of members for guiding the movement of the armature along an axis in said plane and a pair of portions on the frame each respectively engaging a sidewall portion on one of the pair of molded members for preventing movement of the armature along an axis in the plane that is parallel to the rear surface of the base during the movement of the armature and carrier between the energized and deenergized positions.
 2. The combination as recited in claim 1 wherein the base includes a slot centered in the planes extends in the rear wall and through the sidewalls and a plurality of spaced passages centered in the plane and extend between a front side of the slot and the front side of the base and the bight portion of the carrier is movable in the slot, the arm portions extend externally of the sidewalls of the base and the projections extend forwardly from the bight portion and through the passages.
 3. The combination as recited in claim 2 wherein the plane is centered between a pair of end walls of the base.
 4. The combination as recited in claim 3 wherein each of said members is formed of a molded material and has an arcuate surface which is engaged by one of said portions on the frame.
 5. The combination as recited in claim 4 wherein the armature includes a stack of laminated magnet metal parts which provide the opposite ends and pole faces and a pair of nonmagnetic metal members each having a length greater than the length of the magnet metal parts and wherein the nonmagnetic members are secured to opposite sides of the stack to provide portions extending from each of the opposite ends of the stack to which the molded members are secured.
 6. The combination as recited in claim 2 wherein the movable contact carrier has a bearing surface located centrally on its bight portion and the slot has a portion which cooperates with the bearing surface to guide the movement of the bight portion during the movement of the armature.
 7. The combination as recited in claim 6 wherein the plane is centered between a pair of end walls of the base.
 8. The combination as recited in claim 7 wherein each of said members is formed of a molded material and has an arcuate surface which is engaged by one of said portions on the frame.
 9. The combination as recited in claim 8 wherein the armature includes a stack of laminated magnet metal parts which provide the opposite ends and pole faces and a pair of nonmagnetic metal members each having a length greater than the length of the magnet metal parts and wherein the nonmagnetic members are secured to opposite sides of the stack to provide portions extending from each of the opposite ends of the stack to which the molded members are secured.
 10. The combination as recited in claim 6 wherein each of the nonmagnetic metal members has an L-shaped cross section and the molded member is secured to the extending portions by screws which are received in threaded openings in an arm portion of the L-shaped members. 